Plate heat exchangers, as they are referred to, which are formed from a stack of plates lying next to one another are known. Between the plates, cavities are formed, through which a first and a second medium flow alternately.
As well as use as a cooler, in which case, for example, the first medium is cooling water and the second medium is the working medium to be cooled, the engine oil where an oil cooler/internal combustion engine is concerned, use as an evaporator of a cooling apparatus, such as a vehicle air conditioning system, may also be envisaged, in which case one of the two media is the coolant and the other is the refrigerant.
In this context, it is known that the plates are profiled so that contact points occur between the plates. The plates are fastened to one another in the region of the contact points. Furthermore, on the outside, the plates bear sealingly one against the other, so that the cooling medium or the working medium flows solely through the cavity. The first and the second medium are thus in each case supplied through a corresponding inflow line and discharged via an outflow line. Inflow lines and outflow lines thus in each case serve as collecting lines in which the fluid stream is respectively supplied to and discharged from all the corresponding cavities.
Conventionally, in plate heat exchangers, turbulence-increasing fittings for improving the heat transmission and for surface enlargement are introduced into the fluid ducts and are connected firmly to the heat-exchanging plate. As a result, not only the thermodynamic property of the duct, but also the strength property of the cooler are greatly improved.
One disadvantage of such turbulence plates is that chip formation easily occurs during the production of the passage orifices and may lead to contamination of the medium flowing through. Furthermore, dirt is easily deposited in the region of the turbulence plates. The throughflow of the cavity may thereby be impeded in an undesirable way. Moreover, they constitute an additional component to be produced which makes the heat exchanger more expensive on account of increased production costs and material costs.